Our objective is to develop an objective and reproducible method for determining the malignant potential of uveal melanomas from histopathologic examination. In order to achieve this objective, we will measure the cytologic features from the microslides of several hundred uveal melanomas selected from the registry of Ophthalmic Pathology (Armed Forces Institute of Pathology). After comparing these measurments with the clinical course of the patients from whom the tumors were removed, we will select those cytologic features that are useful for predicting death from metastasis. With this information we will develop objective criteria for estimating the malignant potential of newly diagnosed cases of uveal melanoma. Ultimately, concepts derived from the study of this relatively controlled neoplastic system will be applied to other neoplasms in an attempt to predict their malignant potential.